What is a Fact Family?
Fact families are groups of three numbers that are related to one another. You can create fact families for addition and subtraction and for multiplication and division. Today we will concentrate on addition and subtraction.
Most addition and subtraction fact families can be put together to create four different number sentences - two addition and two subtraction number sentences.
For example, let’s look at the numbers 3, 5 and 8. They form a fact family and can make the following number sentences:
3 + 5 = 8
5 + 3 = 8
8 - 5 = 3
8 - 3 = 5
Addition and Subtraction Fact Families
Depending on the age of your students, you can have fun creating stories about your fact families. When I introduce fact families, I always refer to the largest number as the dad, the middle number as Mum and the smallest number as Baby. Dad always looks after his family, so he always goes at the end of an addition number sentence and at the beginning of a subtraction number sentence.
We always locate the dad first. Look at this fact family. The largest number is 8 so that is Dad. We can put him at the end of the addition sums, and at the beginning of the subtraction sums.
Then we fill in the addition sums. Mum plus Baby, then we turn them around - Baby plus Mum. We call this the “turn-around fact”.
If necessary, you can use manipulatives at this stage to demonstrate the turn-around fact.
I like to use dominoes. Show your students the two and six domino. How many dots altogether? Now turn the domino around. How many dots now?
Now for the subtraction. Dad is always there at the beginning. First, take away Mum and Baby is left. Then, take away Baby and Mum is left. Use the domino, cover the six (Mum) to take it away and you’re left with 2 (Baby). Turn the domino around and cover the two and you’re left with six. - the turn-around fact.
Fact Family Triangles
Fact Family Triangles are triangle shapes that have each fact family member placed in the corners of the triangle. Generally the largest number (Dad) is at the apex of the triangle.
Here are three ways you can use Fact Family Triangles in your classroom:
Attach a Fact Family Triangle to a personal whiteboard. This is the roof of the fact family house. Have your students draw the house below the roof and write in the four related number sentences.
Play “Round the World”. Students sit in a circle on chairs. First challenger stands behind another student. Teacher shows a fact family triangle and the first student to call out a related number sentence gets the chance to give all the related fact family number sentences. If they are successful, they move to stand behind the next student in the circle. If unsuccessful, the student sitting down moves to the next student.
Hold up a Fact Family Triangle and cover one of the numbers. Students guess the covered number and then write the related number sentences.
If you would like a free copy of a set of Fact Family Triangles click HERE and scroll to the bottom of the page. Sign up to get the password which will give you access to my FREE RESOURCE LIBRARY.
Fact Family Games and Resources
Once your students understand fact families and how they are formed, this set of Boom Cards, available HERE, make be a fun way to practise and achieve greater fluency.
This resource - Fact Families The Game - is also available and has always been a student favourite!
Click HERE to check it out!
If you know how to play “Go Fish” then you know how to play Fact Families The Game!
Look what teachers are saying about this game:
And lastly, a game that we call, Find My Family!
Create cards with four related fact family number sentences, each on a different card. Give each child a number sentence. When the music plays, students walk around the classroom, without talking, looking at each others' cards. When the music stops, the students gather into their fact families and sit on the floor.
Find the Fact Family Number Sentence cards in my FREE RESOURCE LIBRARY. Click HERE and scroll to the bottom of the page. Sign up to get the password which will give you access to your free set of number sentence strips that you can print and use immediately.
I hope that has given you some great ideas on how to teach Fact Families. If you have further ideas you would like to share, please don’t hesitate to leave a comment below.
Acknowledgements:
Fact Family House - www.zipadeedoodahdesigns.com
Dominoes - www.firstgradebrain.com
Laptop - https://bit.ly/2JvrOdH